Method of contacting fluids



atented June 7,

METHOD OF CONTACTING FLUIDS Seymour W. Ferris, Mount Holly, N. 3., and Edward R. Lamson, Hatboro, and Douglas M. Smith, Norwood, Pa., assignors to The Atlantic Refining Company, Philadelphia, Pa., a corporation of Pennsylvania Application March 21, 1946, Serial No. 656,126

8 Claims.

The present invention relates to a method of contacting a plurality of fluids, and relates more particularly to the contacting of liquids with gases or with other immiscible or partially immiscible liquids.

In accordance with this invention, one of the fluids is formed into a guided free film, and such film is intimately contacted with a second fiuid without rupturing the guided free film, and the fluids are thereafter separated. In a more specific aspect of the invention, one of the liquids is formed into a guided free film, the film is flowed in countercurrent contact with a second partially immiscible fluid without rupture of the film, and thereafter the film is ruptured and the resulting fluid is separated from the partially immiscible fiuid.

The method of the present invention is adapted in the treatment of a great variety of fluids, and is characterized by the efficiency of contact between the fiuids and the avoidance of the formation of emulsions or dispersions diflicult of resolution.

Processes requirin the contacting of two or more immiscible or partially immiscible fiuids are exemplified by the desaltin of petroleum by extraction with water or salt solutions; the separation of hydrocarbon mixtures such as lubricating oil stocks into liquid paraffinic and" liquid naphthenic oil fractions by selective extraction with, partially immiscible solvents such as nitrobenzene, nitrotoluene, liquid sulfur dioxide-benzol mixtures, dichlordiethyl ether, furfural, cresylic acid, chloraniline, chlorphenol, and the like; the desulfurization of hydrocarbon mixtures such as petroleum or fractions thereof by xtraction with aqueous or aqueous alcoholic solutions of bases such as alkali metal hydroxides, amines, etc.; the removal of oil-soluble sulfonates from acid treated. neutralized hydrocarbon oils by extraction with aqueous or non-aqueous solvents; the neutralization and removal of organic and inorganic acids from petroleum o-ils by extraction with aqueous or aqueous alcoholic solutions of alkalis; the removal of phenolic compounds from tar oils by extraction with solvents or with solutions of alkalis; the neutralization and removal of fatty acids from fatty oils by extraction with alkali solutions; the removal of nitrogenous bases from hy-' drocarbon oils by extraction with acids or aqueous solutions of acids; the alkylation of liquid mixtures of isoparafiins with olefins or of aromatic hydrocarbons with olefins or alcohols in the presence of acid catalysts; the polymerization of liquid olefins with acid catalyst; the refining of 5 oleum; and many other processes involving the contacting of immiscible or partially immiscible liquids.

Processes requiring the contacting of liquids with gases or vapors are exemplified by the partial oxidation of petroleum or petroleum freetions with air or oxidizing gases to produce petroleum acids or blown asphalts; the sulfonation of liquid hydrocarbons with sulfur trioxide; the production of nitrosites and nitrosates by the treatment of liquid olefins with oxides of nitrogen; the romoval of acidic gases such as sulfur dioxide or hydrogen sulfide from gaseous mixtures, particularly hydrocarbon gases, by treatment with aqueous alkalis, phenolate, or alkanolamine solutions; the production of ozonides by the treatment of liquid olefins with ozone; the

sulfurization of hydrocarbon oils, olefinic compounds, and the like with sulfur chloride vapors; the hydrogenation of mineral and fatty oils in the presence of hydrogen or gases rich in hydrogen; the halogenation of mineral, animal or vegetable oils by treatment with chlorine,'bromine, or fiuorine, or the corresponding hydrogen halides; and a variety of other processes requiring the contacting of liquids with gases or vapors.

The present invention may be further-understood with reference to the accompanying drawing in which Figures 1 and 2 represent diagrammatically apparatus suitable for carrying out our 5 process.

. Referring to Figure 1, there is provided a vessel or chamber I which may be jacketed for temperature control, if desired. In the lower section "of the vessel is disposed a horizontal, apertured o baffle 2 which extends over the entire cross section of the vessel. Vertically spaced from the baffle 2 is a distributing plate 3 supporting a plurality of vertical rods or guides 4 suitably spaced from one another and terminating at their upper ends in baffle plate 5 which does not extend completely to the walls of vessel l. The distributing plate 3 is provided with a line of perforations 6 extending between the vertical rods 4. While, for simplicity, only one set of rods 4 and perforations 6 are shown in the drawing, it is apparent that a plurality of sets of rods and perforations in different vertical planes may be provided in order to increase the surface of contact between the fluids, as will be described mor fully hereinafter.

The function of the perforated baflle 2 is to more uniformly distribute and prevent surging of fluid introduced into vessel I below battle 2, while the series of perforations 6 in distributing plate 3 directs the fluid and permits the formation of free liquid films extending vertically between the rods or guides 4. The operation of the apparatus is as follows:

A fluid, for example, an aqueous solution of sodium chloride, is supplied through valve-controlled pipe 'I and pipe 8 to pump 9 from which it is delivered by pipe II) to heat exchanger II, wherein the temperature of the solution is brought, for example, to 80 F., by circulating a heating or cooling medium through the heat exchanger shell, as required. The solution, at proper temperature, is then passed through pipe I2 into vessel I, thereby filling such vessel above distributing plate 3 to a level indicated by line I3. A second fluid, for example, petroleum containing entrained salt, is supplied by means of valvecontrolled pipe I4 and is delivered by pump I5 to heat exchanger I6 wherein the temperature of the oil is adiusted for example, to 80 F. The oil is passed from the heat exchanger I6 through pipe II into the lower section of vessel I beneath the apertured baflle 2, passes up through the apertures, and thence through the series of perforationsii in distributing plate 3. The oil, being of lower specific gravity than the salt solution and being capable of preferentially wetting the rods or guides 4, forms a plurality of thin films extending between the rods, and rises through the salt solution in the form of guided free films. The oil is supplied at the base of vessel I at such a rate that continuous guided trained salt is dissolved from the oil without rupture of the oil films. The films, upon reaching the upper ends of the rods 4, encounter baiiie plate 5 and are ruptured and coalesced, and the oil collects as a layer in the top of vessel I above the interface indicated by line I3. The desalted oil is withdrawn from the top of vessel I by valve-controlled pipe I8 and may be removed from the system, or all or a portion thereof may be recirculated for further treatment by means of valve-controlled pipe I9. reaching the lower section of vessel I above perforated distributing plate 3 is drawn from the vessel by means of valve-controlled pipe 20. If desired, however, such solution may be recirculated by means of valve-controlled pipe 2i for reuse until the extracting power for salt is reduced to an uneconomical level. The rods or guides 4 may be made of metal, plastics, carbon, or ceramic material, and are rendered wettable by the oil, if not normally so, by coating with suitable varnishes, insoluble hydrocarbon The salt solution polymers, resins, silicone films, or other materials preferentially wetted by oil. The horizontal spacing of the rods is governed by the characteristics of the fiuid from which the films are to be formed, and by the rate of flow of the films. Such horizontal spacing may range, for example, from to 3 or 4 inches, and with a plurality of rods so spaced, the aggregate width of the film may attain many feet. The length of the rods, and consequently the length of the film is governed by the same factors, and film lengths up to 10 feet or more are readily maintained. While, in the above example, oil was desalted by countercurrent contact with an aqueous salt solution, the

oil flowing upwardly as a film and the solution downwardly, it is also possible to reverse the direction of flow of the liquids in the event that the oil has a higher specific gravity than the solution. Furthermore, by suitably choosing the composition of the rods or guides, the treating or extracting liquid may be made to wet the rods and thus form the film, the oil or other immiscible liquid constituting the medium surrounding the film. By operating in accordance with the technique of the present invention, a high contacting efficiency is obtained without the formation of troublesome emulsions normally encountered in conventional contacting methods.

Another aspect of our invention is illustrated in Figure 2 of the drawing which shows apparatus suitable for carrying out the contacting of liquid films with a gaseous or vaporous fiuid. Reierring to Figure 2, an elongated vessel I is provided near the bottom with a horizontal supporting plate 2' apertured or slotted at 3' and carrying a plurality of vertical rods or guides 4' horizontally spaced from one another. In the upper section of vessel I is a distributing plate 5' extending over the cross section of the vessel and provided with a line of apertures 6 in the same plane as the rods 4 and in close proximity to the extremities of the rods. While only one series of rods and line of distributing apertures are shown, it is also possible to utilize a plurality of series of rods and apertures in other vertical planes horizontally spaced from one another.

In operation, a fluid such as hydrocarbon oil is supplied by means of valve-controlled pipe I and pipe 8' to pump 9' whence it is delivered by pipe ID to heat exchanger II wherein the temperature of the oil is raised, for example, to 300 F. by circulating a suitable heating medium through the jacket of the exchanger. The heated oil is then introduced through pipe I2 into the upper section of vessel 1 above the distributing plate 5'. By regulating the rate of pumping, a constant head of oil may be maintained above the plate 5 while the oil is fed through the apertures 6 in a plurality of fine streams which coalesce immediately below plate 5 and form a thin film or sheet across the space between rods 4'. The rate of supply of heated oil is adjusted so that a continuously flowing oil film passes downwardly, guided by rods 4, without rupturing until the film reaches the lower ends of the rods and coalesces and drains through the apertures 3' of plate 2' into the bottom of vessel I. During the passage of the oil film downwardly through vessel I, a gaseous fiuid such as air is supplied through valve-controlled pipe I3 and pipe I 4 to pump I5 and is delivered by pipe I6 to heat exchanger I1 wherein the temperature of the air may be raised, if desired, to 300 F. The heated air is then introduced by pipe I8 into the lower section of vessel I and is passed upwardly in intimate countercurrent contact with the downwardly flowing oil film whereby partial oxidation of the oil is effected with the production of oxygenated compounds such as aldehydes, alcohols, and carboxylic acids. The partially deoxygenated air is withdrawn from the upper section of vessel I by means of valve-controlled pipe I9 and may be vented, or all or a portion of such air may be recirculated by valve-controlled pipe 20' for reuse. The partially oxidized oil is withdrawn from the bottom of vessel I by means of valve-controlled pipe 2| and may be passed to storage (not shown) by valve-controlled pipe 22, or all or a portion of such oxiwith said fluid without rupture dized oil may be recirculated by valve-controlled pipe 23' for further oxidation,

While the present invention has been described with reference to Figures 1 and 2 in the treatment of hydrocarbon oil with relatively immiscible fluids, i. e., salt solution and air, respectively, it is apparent that the method may be applied in the contacting of a variety of other immiscible or partially immiscible fluids, a number of which have been set forth hereinbefore. Furthermore, while it is preferable in most cases to efiect contacting of the fluids by countercurrent fiow, it is also possible to utilize concurrent flow, particularly in contacting a liquid with a gas or vapor, or in contacting two liquids when the specific 'gravities thereof are not widely different.

We claim:

1. The method of contacting'a liquid with a partially immiscible fluid, which comprises forming said liquid into an uninterrupted film between a plurality of vertical, horizontally-spaced guides, and bringing said liquid film into intimate contact with said fluid without rupture of said film.

2. The method of contacting a liquid with a partially immiscible fluid, which comprises continuously supplying said liquid between a plurality of vertical, horizontally-spaced guides, said liquid being capable of wetting said guides and thereby forming a thin film therebetween, having two exposed surfaces, and ntinuously flowing said film between said guides in intimate contact of said film.

3. The method of contacting a liquid with a partially immiscible fluid, which comprises continuously supplying said liquid between a plurality of vertical, horizontally-spaced guides, said liquid being capable of wetting said guides and thereby forming a thin film therebetween, having two exposed surfaces, and continuously flowing said film between said guides in intimate countercurrent contact with said fluid without rupture of said film.

4. The method of contacting a liquid with a partially immiscible fluid, which comprises continuously supplying said liquid between a plurality of vertical, horizontally-spaced guides, said liquid being capable of wetting said guides and thereby forming a thin film therebetween, having two exposed surfaces, continuously flowing said film between said guides in intimate countercurrent contact with said fluid without rupture of said film,

' hydrocarbon film and thereafter rupturing said film and separating the resulting liquid from said fluid.

5; The method of contacting a liquid hydrocarbon mixture with a fluid partially immiscible therewith, which comprises continuously supplying said liquid hydrocarbon mixture between a plurality of vertical, horizontally-spaced guides, said liquid hydrocarbon mixture being capable of wetting said guides and thereby forming a thin film therebetween having two exposed surfaces, and continuously flowing said liquid hydrocarbon 6 film between said guides in intimate contact with said fluid without rupture of said film.

6. The method of contacting a liquid hydrocarbon mixture with a fluid partially immiscible therewith, which comprises continuously supplying said liquid hydrocarbon mixture between a plurality of vertical, horizontally-spaced guides, said liquid hydrocarbon mixture being capable of wetting said guides and thereby film therebetween having two exposed surfaces, and continuously flowing said liquid hydrocarbon film between said guides in intimate countercurrent contact with said fluid without rupture of said film.

7. The method of contacting a liquid hydrocarbon mixture with a fluid partially immiscible therewith, which comprises continuously supplying said liquid hydrocarbon mixture between a plurality of vertical, horizontally-spaced guides, said liquid hydrocarbon mixture being capable of wetting said guides and thereby forming a thin film therebetween having two exposed surfaces, continuously flowing said liquid hydrocarbon film between said guides in intimate contact with said fluid without rupture of said fllm, and thereafter rupturing said liquid hydrocarbon film and separating the resulting liquid hydrocarbons from said partially immiscible fluid.

8. The method of extracting a component from a liquid hydrocarbon mixture with a solvent which is partially immiscible therewith, which comprises continuously supplying said liquid hydrocarbon mixture between a plurality of vertical, horizontally-spaced guides, said liquid hydrocarbon mixture being capable of wetting said guides and thereby forming a thin film therebetween having two exposed surfaces, continuously flowing said liquid hydrocarbon film between said guides in intimate countercurrent contact with said partially immiscible solvent to dissolve said com ponent without rupture of said liquid hydrocarbon fllm, and thereafter rupturing said liquid and separating the resulting liquid hydrocarbons from said partially immiscible solvent containing the dissolved component.

SEYMOUR W. FERRIS. EDWARD R. LAMSON. DOUGLAS M. SMITH.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS forming a thin countercurrent 

